Baby-food compositions containing egg yolk and methods therefor

ABSTRACT

Baby-food compositions containing about 5% to about 25% egg-yolk solids and an acidulant in an acceptable, shelf-stable, baby-food preparation is set forth. The acidulant can be an acid, a cultured food substance containing lactic acid or a fruit or vegetable component which contributes acidity to the composition or a combination thereof. Also described are methods for preparing and using the compositions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/082,634 filed May 21, 1998 now U.S. Pat. No. 6,149,964.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates generally to food compositions and, moreparticularly, to novel baby-food compositions comprising egg yolk and tomethods of making and using the compositions.

(2) Description of the Related Art

Semi-solid baby-food compositions containing egg-yolk solids arecurrently available commercially in the United States and a number ofother compositions not currently available are known to have beenavailable in the past. However, all of these compositions have containedeither a small amount of egg-yolk solids, i.e. less than 5%, or a largeamount of egg-yolk solids, i.e. about 29% to 30% or more, neither ofwhich is entirely satisfactory as a food source. The compositionscontaining less than 5% egg-yolk solids do not provide the amount ofnutritional components available in the compositions having higherpercentages of egg yolk, whereas, baby-food compositions with the higherpercentages of egg yolk have had extremely poor taste and, as a result,they are no longer commercially available. Indeed, it is well known thatinfants typically reject cooked egg yolk, apparently because of itsstrong taste and gritty, mealy texture. Nevertheless, because egg-yolksolids are known to contain substantial levels of nutrients, thereremains a continuing need for a semi-solid baby-food compositioncontaining moderate to high levels of egg-yolk solids in a compositionsuitable for feeding to babies.

Among the nutrients which can be added to the infant diet in egg-yolksolid are the polyunsaturated fatty acids. One such polyunsaturatedfatty acid, the ω-3 fatty acid, docosahexaenoic acid (DHA), has beenshown to be a required nutrient for optimal maturation of visual andcortical function in human infants (See, for example, Hoffman et al.,Am. J. Clin. Nutr. 57(suppl.):8075-12S, 1993; Makrides et al., Lancet345:1463-1468, 1995). Although the minimum dietary amount of DHArequired by infants has not been unequivocally established, the Food andAgriculture Organization and World Health Organization recommend 40mg/kg body weight for preterm infants and 20 mg/kg for term infants(FAO/WHO Expert Consultation on Fats and Oils in Human Nutrition, FAO1994, Rome, pp. 52-55). For term infants this is about 70 mg at birth inabout 420 calories and 140 mg at 6 months of age in about 700 calories.

Breast-fed infants receive DHA in their mother's milk, which contains afull-complement of both ω-6 and ω-3 polyunsaturated fatty acids (Hoffmanet al, supra; Makrides et al., supra; Innis et al, Am. J. Clin. Nutr60:347-352, 1994). However, the concentration of DHA in breast milk canvary substantially depending upon the amount of preformed DHA from meatand fish in the mother's diet. Id. In addition, many infants are notbreast-fed or are breast-fed only for a few weeks and must rely oninfant formula and solid baby food for their nutritional requirements.

Current infant formulas available in the United States do not containDHA (Jensen et al., J. Pediatr 131:200-209, 1997). Furthermore, solidfoods fed to babies generally have little or no DHA so that the intakeof fat from such solid foods does not increase plasma DHA levels as doesbreast feeding (Luukkainen, supra). Thus, it would be desirable toincrease the dietary intake of DHA in babies and one way to accomplishthis would be to increase the amount of DHA either in infant formula orin solid baby-food compositions.

Sources of DHA that have been added to infant formula to increase thecontent of DHA include marine oil, extracted egg-yolk lipids and lipidsderived from animal tissue phospholipids (U.S. Pat. No. 4,670,285, Uauy,et al., .J Pediatr. 134:612-620, 1994; Makrides et al., supra; Carlson,J. Nutr.:126:10925-10985, 1996). However, marine oil tends to have astrong fishy taste and odor and thus is unsuitable for adding to infantformula or solid baby food. In addition, lipids extracted from egg yolkand animal tissue are susceptible to oxidative deterioration. Also, withrespect to solid baby-food preparations, production of fish and/oranimal oils requires extensive processing, so that the use of suchprocessed oils in a baby-food composition would diverge from the “wholefood” and “natural food” concepts of baby food which is popular amongcaregivers.

One possibly suitable source of DHA that might be incorporated into asolid baby-food preparation is whole egg yolk. Although, hens' eggsordinarily contain only very low amounts of DHA, hens fed a dietenriched with DHA or DHA precursor can contain about 80 mg/egg yolk orabout 10 mg/gram of egg-yolk solids. See Table 1, infra. SuchDHA-enriched eggs have been developed as sources of DHA for humanconsumption (Herber et al., Poultry Sci 75:1501-1507, 1996; Oh, U.S.Pat. No. 5,415,879). Nevertheless, this earlier work provided nosuggestion as to how such DHA-enriched eggs might be incorporated intoan acceptable semi-solid baby-food preparation. Thus, there remains acontinuing need for a semi-solid baby-food composition containingegg-yolk solids including egg-yolk solids from eggs enriched with anatural source of DHA, in a composition suitable for feeding to babies.

SUMMARY OF THE INVENTION

Accordingly, the inventors herein have succeeded in discovering how toproduce acceptable baby-food composition containing 5 to 25% egg-yolksolids. Because egg yolks contain substantial levels of nutrients suchas high quality protein with all of the essential amino acids, manyvitamins and minerals, and polyunsaturated fatty acids, the baby-foodcompositions of the present invention are useful in contributing to thenutritional quality of the infant diet. Furthermore, egg-yolk solids canserve as delivery vehicles for nutrients such as the polyunsaturatedfatty acid, DHA, if the eggs are produced by chickens fed diets high inDHA or DHA precursors.

Thus, in one embodiment, the present invention provides a novelbaby-food composition containing from about 5% to about 25% egg-yolksolids. In one aspect of this embodiment, the egg-yolk solids are highin DHA content so as to provide nutritionally significant amounts of DHAin the infant diet in only one or two servings. As a result, thebaby-food composition, preferably, contains at least 1 mg DHA per gramof the composition. Because the DHA in the baby-food compositions of thepresent invention is provided by egg yolk rather than by adding refinedoils or fats, the compositions are whole food preparations. Furthermore,eggs containing high amounts of DHA have been consumed by humans for anumber of years so that one would not anticipate encountering anyunexpected adverse effects upon feeding compositions containing theDHA-enriched egg yolks to babies.

The new compositions are in an acceptable baby-food formulation whichfurther comprises an acidulant selected from the group consisting ofcitric acid, phosphoric acid, vinegar or combinations thereof. As analternative to or in addition to such acids, the acidulant can becomprised of a cultured food substance containing lactic acid asillustrated below in Examples 11 and 16 or one or more fruit orvegetable components which contribute acidity to the composition asillustrated below in Examples 4, 14, 15 and 16. Moreover, thecompositions can contain additional ingredients including a zinc salt, aspice, an additional fruit or vegetable component which contributesorganoleptic qualities such as flavor or aroma to the composition and afiller substance, such as starch or flour.

In another embodiment, the present invention comprises a method forincreasing the nutritional intake of an infant. The method comprisesfeeding to the infant, a baby-food composition containing from about 5%to about 25% egg yolk. In one aspect of this embodiment, the compositioncontains at least 1 mg DHA per gram of the composition. The newcompositions are in an acceptable baby-food formulation which furthercomprises an acidulant selected from the group consisting of citricacid, phosphoric acid, acetic acid or combinations thereof. As analternative to or in addition to such acids, the acidulant can becomprised of a cultured food substance containing lactic acid asillustrated below in Examples 11 and 16 or one or more fruit orvegetable components which contribute acidity to the composition asillustrated below in Examples 4, 14, 15 and 16. The acidulant orcombination of acidulants confers upon the composition of a pH of about4.6 or less. Moreover, the compositions can contain additionalingredients including a zinc salt, a spice, an additional fruit orvegetable component which contributes organoleptic qualities such asflavor or aroma to the composition and a filler substance such as starchor flour.

The present invention, in still another embodiment, provides a methodfor preparing a baby-food composition containing egg-yolk solids. Themethod comprises (a) mixing egg-yolk solids and an aqueous liquid toproduce an egg-yolk mixture, (b) coagulating egg-yolk protein in themixture, and (c) homogenizing the coagulated egg-yolk mixture. Thebaby-food composition is prepared so that it contains from about 5% toabout 25% egg-yolk solids. The method can further comprise adding anacidulant to adjust the pH to a value of about 4.6 or less. Preferablythe acidulant is added as part of step (a) or after step (a) and beforestep (b). The acidulant is one that is acceptable for use in a baby-foodformulation such as citric acid, phosphoric acid, vinegar orcombinations thereof. As an alternative to or in addition to such acids,the acidulant can be comprised of a cultured food substance containinglactic acid as illustrated below in Examples 11 and 16 or one or morefruit or vegetable components which contribute acidity to thecomposition as illustrated below in Examples 4, 14, 15 and 16. Themethod can further comprise independently adding as part of step (a) orat any time thereafter, a zinc salt, a spice, an additional fruit orvegetable component which contributes organoleptic qualities such asflavor or aroma to the composition, a filler substance or a combinationthereof.

Among the several advantages achieved by the present invention,therefore, may be noted the provision of a composition and method thatcan nutritionally enrich the infant diet by incorporating egg-yolksolids in the composition; the provision of compositions and methodsthat can serve as a source of DHA in the infant diet; the provision ofsuch compositions in an acceptable baby-food formulation that meetapplicable regulatory requirements as well as being acceptable to thebaby and caregiver; and the provision of a new method for manufacturinga food composition containing egg-yolk solids.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is based upon the discovery that a significantamount of egg yolk can be incorporated into acceptable baby-foodcompositions. The term baby or infant as used herein is intended to meana child in the first period of life generally considered to be in theage range of from birth to about four years and an acceptable baby-foodcomposition is intended to encompass semi-solid food preparationsdesigned for feeding to such baby or infant and meeting all of theregulatory and organoleptic requirements for such compositions. Althoughdesigned as baby-food compositions and referenced as such herein, thecompositions within the present invention can, of course, be consumed byother population groups such as by individuals who are sick or those whohave special nutritional requirements and, in particular, by geriatricindividuals so long as the compositions are in an acceptable baby-foodformulation.

The baby-food compositions of the present invention can compriseegg-yolk solids in an amount from about 5% to about 25% egg-yolk solids,more preferably, from about 6% or about 7% to about 25%, even morepreferably from about 10% to about 20%, still more preferably, fromabout 12% to about 18%, even still more preferably from about 14% toabout 16% and most preferably, about 15%. The term “about” is intendedto included variances of 0.5 percentage values above and below indicatedvalues so that about 15% is intended to mean 14.5% to 15.5%.

The term egg-yolk solids is intended to mean the solids present innatural egg yolk or in dried egg-yolk products such as those commonlyused as ingredients in the food industry. The egg-yolk solids can be inthe yolk of a whole hen's egg as separated from the shell or in an eggyolk separated from the whole hen's egg or in a purified form in whichsome or all of the water has been removed from the egg yolk. The amountof solids in egg yolk from hens' eggs and dried egg-yolk products, canbe determined using known methods, and are typically about 46% and about96%, respectively.

As noted above, certain baby-food compositions containing egg yolk arecurrently commercially available while other baby-food compositionscontaining egg yolk were available in the past but are no longeravailable. However, none of these compositions are believed to havecontained from about 5% to about 25% egg-yolk solids (see Example 1below).

In one embodiment, the egg-yolk solids contain high levels of DHA as aresult of being produced from eggs laid by hens fed a diet enriched withDHA or DHA precursors such as one containing DHA from marine algae, fishoil or other source of DHA or alpha-linolenic acid from flaxseed orcanola or soybean. (see, for example, Herber et al., supra; Oh, supra;Abril et al., International Conference on The Return of ω-3 Fatty AcidsInto the Food Supply: I. Land-Based Animal Food Products and TheirHealth Effects, Sep. 18-19, 1997; Scheideler et al., InternationalConference on The Return of ω-3 Fatty Acids Into the Food Supply: I.Land-Based Animal Food Products and Their Health Effects, Sep. 18-19,1997). Such DHA-enriched eggs are commercially available and their yolksolids can typically contain from about 9 to about 19 mg DHA/g. Theamount of DHA in egg-yolk solids can be measured using methods known inthe art (see Example 2 below). Preferably, the source of DHA-enrichedegg yolk and/or the amount of DHA-enriched egg-yolk solids is selectedsuch that the baby-food composition comprises sufficient DHA to providethe minimum daily recommended amount of about 20 mg/kg/day or about 70mg for the newborn and about 140 mg for the 6 month infant in one or twoservings. For example, a typical jar of commercial baby food for sixmonth infants contains four ounces or 113 grams of baby-foodcomposition. The composition can be prepared to contain 150 mg DHA per100 g of baby food, which would amount to 165 mg DHA per jar. Thisamount of DHA could be provided by DHA-enriched egg yolks containing 12mg of DHA per gram egg-yolk solids and the composition would thuscontain 14 grams egg-yolk solids per jar or about 12.5% egg-yolk solids.

The egg yolk containing compositions of the present invention are inacceptable baby-food formulations. The terms acceptable baby-foodformulation are used interchangeable herein with the terms acceptablebaby-food composition and acceptable baby-food preparation. Anacceptable baby-food formulation is one suitable for feeding to a babyand included within the meaning of the terms acceptable baby-foodformulation is any regulatory agency requirements for foods intended forconsumption by infants. For example, lactic acid and malic acid havebeen reviewed by the Food and Drug Administration and determined not tobe generally recognized as safe for use in baby foods. (see 21 C.F.R.§184.1061, §184.1069). Thus, these acids would not be incorporated intoan acceptable baby-food formulation. On the other hand, the use ofcitric acid and phosphoric acid have been determined to be generallyrecognized as safe (see 21 C.F.R. §184.1033, §182.1073). Therefore,these acids can be incorporated into an acceptable baby-foodformulation.

In addition, an acceptable baby-food formulation is one whose overallcombination of organoleptic characteristics, i.e., taste,mouthfeel/texture, odor and color/appearance, is sufficientlysatisfactory that the infant will consume the formulation and thecaregiver will serve the formulation to the infant. For example, infantsare known to display an aversion to bitter tastes at a very early ageand to strong flavors such as can be present in some vegetables (Trahms,in Nutrition in Infancy and Childhood, Pipes and Trahms, Eds, Mosby, St.Louis, 1993, pp. 181-194; Kajiura et al, Developmental Psychobiol25:375-386; Rosenstein et al., Child Develop 59:1555-1568, 1988;Lowenberg, in Nutrition in Infancy and Childhood, Pipes and Trahms, Eds,Mosby, St. Louis, 1993, pp. 165-180; Brooks, supra; Lawless, supra;Ashbrook et al, J Nutrition Ed 17:5, 6, 46, 1985; Beal Pediatrics20:448-456, 1957). Therefore, an acceptable formulation of a baby-foodcomposition does not have a strong bitter taste or a strong flavor suchas can be present in some vegetable preparations.

An acceptable baby-food formulation will also have a texture that isacceptable to the baby. For example, foods that are too dry or grittyare usually unacceptable to infants. In general, acceptable baby-foodformulations will be smooth in texture. In addition, younger infantstypically prefer food that is soft and homogenous. For older infants,however, a nonhomogenous texture may be desired. Because of suchpreferences, baby foods are typically produced in different forms,depending on the age of the intended consumer. For example, BEECH-NUTStage 1 products are intended to be consumed by babies from about threemonths of age. BEECH-NUT Stage 2 products, which are strained and willpass through a 0.050″ orifice, are intended to be consumed by infantsfrom about six months of age. Infants of about nine months of age andolder are the intended consumers of BEECH-NUT Stage 3 Junior products,which have chunky components that will pass through a ⅜ inch screen.

Preferably, the desired texture can be achieved using the whole foodconcept by mixing whole food preparations having the desired texture.The whole food concept involves minimal preparation of food componentssuch as by cleaning, peeling and comminuting the food as distinguishedfrom further processing such as by drying, milling into a flour and/orfurther refining.

Moreover, the color and appearance of the formulation are such that theinfant or the adult caregiver will not reject the formulation.Acceptable colors tend to be light rather than dark. Preferably,acceptable color is achieved using the whole food concept in which foodcomponents are added which produce the desired color for the overallmixture. The appearance of the formulation should also be smooth andhomogenous.

In addition, the composition should not produce adverse side effectssuch as acid indigestion, diarrhea, allergic responses or the like.

Testing a baby-food composition for organoleptic acceptability can bereadily performed by the skilled artisan using routine methods such asthose described in the Examples below. For example, since the adultperception of bitter tastes closely follows that in the infant (Lawless,J. Am. Diet. Assoc. 85:577-585, 1985) and since food preferences oraversions of the adult caring for the infant are known to influencewhich foods are offered to the infant (Trahms, in Nutrition in Infancyand Childhood, Pipes and Trahms, Eds, Mosby, St. Louis, 1993, pp.181-194; Brooks, The Wall St J, Dec. 4, 1996 pp A1, A6), it is possibleto conduct acceptability testing in adults. Standard testing proceduresfor sensory evaluation are known in the art including, in particular, a9-point hedonic scale as described in Example 9 below (see Stone andSidel in Sensory Evaluation Practices, Academic Press, Orlando, 1985, pp58-86, 227-252). Sensory characteristics which can be tested includeappearance and color, flavor, and mouthfeel and texture. Compositionsscoring above neutral on a 9-point hedonic scale, i.e. 5.0 or greater,for at least one, more preferably two and most preferably all sensorycharacteristics of appearance/color, flavor and mouthfeel/texture areconsidered to be acceptable with respect to those attributes.

Testing for organoleptic acceptability in infants could be conducted,for example, after obtaining informed consent from parents in adouble-blind, randomized controlled study. Infants of ages from about 4months to about 12 months would be fed a series of baby-foodcompositions prepared containing, for example, 15% egg-yolk solids or areference baby-food preparation known to be accepted by the infants suchas, for example, BEECH-NUT and GERBER vanilla custard pudding productsor GERBER cherry vanilla pudding product. The adult feeding the infantwould then record acceptability and tolerance including amount offered,amount consumed and amount refused by the babies. Acceptability ratingwould be performed by methodology known in the art (for example, Stoneand Sidel, supra). The results would be analyzed and compositionsshowing acceptance comparable to or greater than that of the referencebaby food would be considered organoleptically suitable for use as aninfant food.

The baby-food compositions of the present invention can also contain anaqueous liquid comprising water or a solution containing water. Theaqueous liquid is added in an amount that confers a smooth texture onthe composition as a whole. Preferred aqueous liquids include water,fruit juices such as apple juice, grape juice, orange juice, and thelike and vegetable juices such as carrot juice, beet juice, celeryjuice, tomato juice and the like. The use of fruit juices and somevegetable juices can also provide a source of sugars for thecomposition.

Preferred embodiments of the present invention also contain anacidulant. The acidulant improves the texture and/or mouthfeel of theegg yolk containing compositions to produce a smooth texture.Furthermore, the addition of acidulant to achieve a pH of 4.6 or lesspermits the sterilization of the composition at a temperature of 212° F.rather than at 250° F. temperature required for compositions having ahigher pH. This lower retorting temperature not only simplifies themanufacturing procedure, it improves the color of the processedbaby-food composition and reduces any heat-induced breakdown of itsnutrients compared to retorting at 250° F. temperature required forcompositions having a higher pH. The acidulant is, thus, preferablypresent in an amount sufficient to produce a post-processing pH of 4.6or less and most preferably in the range of between 4.2 and 4.3.

The acidulant of the present invention can be any acid permitted underapplicable regulatory agency rules for use in infant foods. Inparticular phosphoric acid, citric acid, vinegar, and combinationsthereof are suitable for use in an acceptable baby-food preparation. Asan alternative to or in addition to such acids, the acidulant can becomprised of a cultured food substance containing lactic acid asillustrated below in Examples 11 and 16 or one or more fruit orvegetable components which contribute acidity to the composition asillustrated below in Examples 4, 14, 15 and 16. Examples of culturedfood substances containing lactic acid include, but are not limited toyogurt, sour cream, cottage cheese, sauerkraut and the like. Examples ofsuitable fruits or vegetables include, but are not limited to apples,pears, pineapples, strawberries, raspberries, elderberries, blueberries,cherries, grapes, peaches, plums apricots, lemons, clementines,grapefruits, oranges, tomatoes, rhubarbs, sorrels, cress and the like.The fruit or vegetable component is preferably in the form of a puree orjuice. The term juice as used herein is intended to include juices andconcentrates thereof.

The acid should not make the composition organoleptically unacceptablenor should the acid deleteriously affect the infant in any way.Phosphoric acid, although acceptable in many embodiments, is sometimesless desirable for use in a baby-food compositions of the inventionbecause it adds additional phosphorus to the diet as do the egg-yolksolids. Thus the use of phosphoric acid should be in amounts such thatthe total of phosphorus in the composition as a whole does not result inconsumption by the infant exceeding the recommended daily intake forphosphorus of 500 mg. For preparations in which the composition as awhole would provide a daily intake of greater than 500 mg phosphorusbecause the egg-yolk solids or other components in addition to thephosphoric acid contribute excessive amounts of phosphorus, phosphoricacid would not be an acceptable acidulant.

The acidulant in the form of an added acid can also improve the taste ofthe composition, particularly, when in combination with a fruit puree orjuice in the composition. Thus, the tartness of the acid can tend toprovide a balance with fruit components or with added sugar in thecomposition.

The baby-food compositions of the invention can comprise ingredientswhich enhance the acceptability of the composition to an infant. Forexample, fruit(s) and/or vegetable(s), including purees and juicesthereof can not only serve as acidulants as noted above, but they canalso enhance the acceptability of the composition. As also noted above,the juices can serve to add water as can purees to a lesser extent. Bothpurees and juices can contribute sugars and additional desirable flavorcomponents to the composition. Examples of suitable fruits that can beincorporated in puree or juice form include apples, pears, bananas,pineapples, strawberries, mangos, papayas and the like. Vegetables whichcan be incorporated in puree form can include sweet potato, beets,carrots, celery and the like.

Additionally, filler substances such as corn starch, rice flour, wheatflour, nonfat dry milk and the like can be included in the compositionas can flavoring agents such as sugars, spices and the like. Inparticular, cinnamon can be included in the composition.

Other substances can additionally be added to the composition to improvethe flavor of the composition. For example, zinc salts such as zincsulfate or zinc chloride can tend to neutralize the sulfurous odor andtaste of cooked egg yolk. In addition, the added zinc can provide anutritionally significant source of zinc. In addition to zinc, othernutritional supplements such as vitamins and/or minerals can also beincorporated into the composition.

In certain embodiments, coloring agents, processing agents orpreservative agents can also be added such as, for example, to improvecolor, taste, shelf life and the like.

Additional components of baby-food compositions within the scope of thepresent invention can include, for example, pasta preparations, meatpreparations such as turkey or beef, other protein-containing foods andthe like.

Preferably, the formulation is based upon a whole food concept such thatindividual constituents conferring the desired properties on thecomposition are prepared foods rather than dried and/or refinedsubstances or artificially prepared substances. The whole foods areprepared such as by cleaning, peeling, and comminuting the whole food orpart thereof. Examples of whole food components of baby-foodcompositions are fruit juices which can be used as a natural source ofsugars and vegetables such as white carrots which can be used as fillersinstead of a starch substance (see, for example, U.S. Pat. No.5,723,166).

The present invention also provides a method of making the acceptablebaby-food compositions described above. The method involves combiningthe desired quantity of egg-yolk solids, in the form of whole egg yolkor dried egg yolk or the like, with an aqueous liquid and blending toproduce a mixture of smooth consistency. The aqueous liquid can be wateror any of a number of fruit juices such as, for example, apple juice,grape juice, orange juice, and the like or vegetable juices such ascarrot juice, beet juice, celery juice, tomato juice and the like. Ifdried egg yolks are used, it is necessary to use a sufficient amount ofthe aqueous liquid component to adequately disperse the egg-yolk solidsin the mixture. The amount of egg-yolk solids in the composition as awhole is preferably from about 5% to about 25%, from about 6% or 7% toabout 25%, from about 10% to about 20%, from about 12% to about 18%, andmost preferably about 15%. The method can further comprise adding anacidulant to adjust the pH to a value of about 4.6 or less. Theacidulant can be added to the initial mixture or after the blending theinitial mixture. The acidulant is one that is acceptable for use in ababy-food formulation such as citric acid, phosphoric acid, vinegar orcombinations thereof. As an alternative to or in addition to such acids,the acidulant can be comprised of a cultured food substance containinglactic acid as illustrated below in Examples 11 and 16 or one or morefruit or vegetable components which contribute acidity to thecomposition as illustrated below in Examples 4, 14, 15 and 16.

The blending, can be accomplished by manual stirring, a mixing machine,a blender or the like and this step can be performed before or after theaddition of any desired additional ingredients. Such blending mixes theingredients and ultimately produces a composition of smooth consistency.

Where additional ingredients are added to the composition such as a zincsalt, a fruit or vegetable puree or juice, a spice or a fillersubstance, such additions can be made at the time the egg-yolk solidsand aqueous liquid are combined or at any appropriate time thereafter.

The blended egg-yolk mixture is then treated to coagulate the protein inthe egg-yolk mixture. This coagulating step can be accomplished byheating the mixture at a temperature, preferably greater than 170° F.and more preferably at least 175° F. Complete coagulation of the eggprotein can be ensured by heating at 180° F. to 190° F. for 5 minutes.Alternative methods can also be used to perform the coagulating stepsuch as, for example, by microwaving the mixture.

The coagulated protein is then dispersed by homogenizing the coagulatedmixture to a smooth consistency. Such homogenizing can be done, forexample by using a blender. The homogenized mixture can then be placedin one or more containers, followed by sealing and heating thecontainers under conditions suitable for producing a shelf-stablecomposition. Such conditions can be readily determined by the skilledartisan and typically involve retorting for about 30 minutes at either212° F., for compositions having a pH of 4.6 or lower, or at 250° F. forcompositions having a pH greater than 4.6.

INDUSTRIAL APPLICATION

The baby-food compositions of the present invention have application foruse as semi-solid preparations for infants. Because the compositionscontain a significant amount of egg-yolk solids, they provide a foodnaturally rich in protein, vitamins and minerals, as well as containingsome polyunsaturated fatty acids. In addition, if the compositions areprepared using eggs yolk solids containing high levels of DHA, thecompositions provide nutritionally significant amounts of DHA in theinfant's diet, which is beneficial for visual and neural development inthe infant.

Preferred embodiments of the invention are described in the followingexamples. Other embodiments within the scope of the claims herein willbe apparent to one skilled in the art from consideration of thespecification and the examples that follow or from practice of theinvention as disclosed herein.

EXAMPLE 1

This example illustrates commercial baby-food compositions containingless than 5% or more than 25% egg-yolk solids.

The compositions of old and current products were obtained from thefollowing publications: BEECH-NUT Ingredient Listings from 1977-1985;GERBER Ingredients Publ. 55-8 Rev. 477 and Publ. 55-8 Rev. 785 foringredients and Publ. 55-85 Rev. 185, Publ. 55-90 Rev. 185, Publ. 55-90Rev. 681 for nutrient values per 100 grams; and BEECH-NUT NutritiveValues & Ingredient Listing, Publ. 1977, Publ. 10/1983.

Calculations below are based upon an egg yolk containing about 46% totalsolids, i.e., about 8 grams total egg-yolk solids for a typical 17-gramegg yolk and fat constituting approximately 50 to 55% of total eggsolids or about 4 grams of fat per average egg yolk.

Two egg-yolk products containing high amounts of egg yolk werecommercially available in the 1970's but are no longer marketed. Thesewere the BEECH-NUT and GERBER “Egg Yolks” products.

The BEECH-NUT “Egg Yolks” product contained egg yolks and water forproper consistency and provided, per 100 grams, 194 calories, 9.6 gramsof protein, 18.5 grams of fat and 29.9 rams of total egg-yolk solids.This product contained 65 grams egg yolk per 100 g.

The GERBER “Egg Yolks” product contained egg yolks and water necessaryfor preparation and provided, per 100 grams, 199 calories, 10.2 grams ofprotein, 17.4 grams of fat and 29.0 grams of total solids, as egg-yolksolids. It is believed that the BEECH-NUT and GERBER Egg Yolk productsare no longer marketed because the compositions were organolepticallyunacceptable to babies and as a result were not purchased by the adultcaregivers.

BEECH-NUT “Cereal Egg Yolks & Bacon” product contained water, farina,smoked bacon, dried egg yolks, modified cornstarch, nonfat dry milk, oatflour and smoked yeast. This product provided, per 100 grams, 86calories, 2.3 grams of protein, 5.5 grams of fat and 15.3 grams of totalsolids. The content of egg yolk was 3.5% dried egg yolk whichcontributed 3.33 grams of egg-yolk solids per 100 grams. GERBER “CerealEgg Yolk Bacon Dinner” contained water, egg-yolk solids, bacon, nonfatdry milk, rice flour, wheat flour, corn flour and sugar. The productprovided, per 100 grams, 66 calories, 2.4 grams of protein, 2.8 grams offat and 13.3 grams of total solids. The amount of egg-yolk solidspresent was estimated to be about 3 grams of egg-yolk solids per 100grams and, in any case, less than 5 grams of egg-yolk solids per 100grams. This calculation is based upon the presumption that the non-eggingredients including the bacon contribute in part to the fat content ofthe composition.

GERBER “Cereal & Egg Yolk” contained water necessary for preparation,nonfat milk, egg yolk, wheat flour, corn flour, modified corn starch,sugar and iodized salt.

This product provided, per 100 grams, 55 calories, 2.3 grams of protein,1.7 grams of fat and 11.8 grams of total solids. The total fat presentis 1.7 grams per 100 grams which would be contributed by less than 4grams of egg-yolk solids per 100 grams.

GERBER and BEECH-NUT desserts contain egg yolks as an ingredient and atotal of 1 gram of fat per 100 grams or less, which indicates less than2 grams of egg-yolk solids per 100 grams.

EXAMPLE 2

This example illustrates the analytical testing of commercial eggsobtained from hens fed diets enriched with DHA or DHA precursors.

Organic eggs from hens fed a DHA-enriching diet were obtained from TheCountry Hen, Hubbardstown, Mass. 01452 and from Pilgrim's PrideCorporation, Pittsburg, Tex. 75686. For comparative purposes, commercialdried egg yolks from hens not receiving DHA-enriching diet were alsoanalyzed.

Whole eggs were used for convenience and because egg white does notinterfere with analytical testing for fatty acids. Fatty acids arepresent almost exclusively in the yolk and the egg whites contain onlynegligible amounts of fat.

Standard AOAC analytical methods were used to quantitatively determinethe fatty acid content in the whole eggs and in the dried egg-yolkcontrol. (see Shepard, Lipid Manual, Methodology Appropriatefor FattyAcid-Cholesterol Analysis, U.S. Food an Drug Administration, Div. ofNutrition, Center for Food Safety and Applied Nutrition, 200 “C” St. SW,Washington, D.C. 20204, Sep., 1989; Official Methods of Analysis of theAOAC, (1995) 16th Ed., Methods 983.23 locator #45.4.02, 969.33 Locator#41.1.28, 994.15 Locator #41.1.35A, and 996.01; Ratnayaka, J. AOACInternational 78:783-802, 1995). Briefly the AOAC method used was asfollows.

Lipids were extracted and then saponified using alcoholic sodiumhydroxide. The fatty acids were then esterified in methanol, with borontrifluoride as catalyst, taken up in heptane and injected on a gaschromatograph with a flame ionization detector. The percentages ofindividual fatty acid methyl esters were determined from a set ofstandards containing known concentrations of prepared methyl esters ofselected fatty acids. The concentration of each fatty acid methyl esterwas calculated as either equivalent triglyceride or fatty acid. Totalfatty acids were calculated as the sum of all fatty acids expressed astriglycerides and the value reported as a percentage, i.e., grams per100 grams of sample. Individual fatty acids were expressed as apercentage of total fatty acids. The analysis was based upon a 2-gramsample and the lowest confidence level for total fatty acids was 0.1%whereas that for individual fatty acids was 0.004%. Results are shown inTable 1.

TABLE 1 Dried Country Pilgrim's Egg Yolk Hen Eggs* Pride eggs* EdibleWeight (g) 51.1 58.4 Fatty acids (g/100 g) 49.44 7.3 9.4 Fatty acids(g/egg) 4.4 5.5 DHA (mg/egg) 89.1 112.2 Fatty Acid (% of total fattyacids) myristic (C_(14:0)) 0.38 0.38 0.38 pentadecanoic (C_(15:0)) ‡0.12 ‡ palmitic (C_(16:0)) 26.04 23.41 21.40 margaroleic (C_(17:0)) 0.230.34 0.29 stearic (C_(18:0)) 9.24 9.48 8.53 palmitoleic (C_(16:1ω7))2.68 1.79 1.50 margaroleic (C_(17:1ω9)) 0.17 ‡ ‡ elaidic (C_(18:1ω9))0.32 ‡ ‡ oleic (C_(18:1ω9)) 40.61 30.0 29.63 vaccenic (C_(18:1ω7)) 1.511.81 1.76 eicosanoic (C_(20:1ω9)) 0.24 0.21 0.20 nervonic (C_(24:1ω9)) ‡‡ ‡ eicosadienoic (C_(20:2ω6)) 0.16 0.26 0.33 linoleic (C_(18:2ω6))12.68 22.84 27.79 gamma linolenic (C_(18:3ω6)) 0.10 ‡ ‡ homo-gamma-lin(C_(20:3ω6)) 0.22 0.28 0.18 arachidonic (C_(20:4ω6)) 1.76 1.28 1.42alpha-linolenic (C_(18:3ω3)) 0.25 1.66 2.37 eicosapentaenoic(C_(20:5ω3)) ‡ ‡ 0.17 docosapentaenoic (C_(22:5ω3)) ‡ 0.26 0.20docosahexaenoic (C_(22:6ω3)) 0.40 2.05 2.04 trans isomers (C_(18:2))0.14 ‡ ‡ unknown 2.22 2.75 1.22 *Values are expressed as means (n = 16for Country Hen eggs and n = 12 for Pilgrim's Pride eggs) ‡ At or belowthe detection limit of 0.10%

As can be seen in Table 1, eggs from hens fed a DHA-enriching diet hadsubstantially higher levels of docosahexaenoic acid (DHA) than dried eggyolk from hens not fed a DHA-enriching diet.

EXAMPLE 3

This example illustrates the testing for the amount of water and acidneeded in an egg-yolk composition suitable for use in a baby-foodcomposition.

Six sample compositions were prepared by dispersing varying amounts ofdried egg yolk in water at room temperature. A preliminary test of acidrequirements was done by adding white vinegar standardized to 5% acidityto sample 7927E to 20% total volume. The samples were placed in aboiling/simmering water bath for about 20 minutes. The samples withgreater amounts of dried egg yolk looked like souffle after cooking. Thesamples were then blended with a hand blender into a smooth mixture andtasted. The results are shown in Table 2.

TABLE 2 Dried Obser- Sample Egg yolk (g) vations Total weight (g)HK7927A 15.2 99.8 before cooking: very thin after cooking: very muchfree fluid. HK7927B 20.4 101.7 before cooking: very thin after cooking:very loose. HK7927C 24.4 100.0 before cooking: very thin after cooking:soft form. HK7927D 30.5 99.6 before cooking: thicker than A, B, or C.after cooking: poor taste, unattractive, no specific dislike exceptgenerally distasteful; puffy; texture soft and wet enough to blend.HK7927E   34.8 + 102.9 before cooking: pretty thick after vinegarcooking: puffy, some vinegar taste but otherwise a nice clean taste; abit thin after stirring, not overly viscous. HK7927F 34.9 99.4 beforecooking: pretty thick after cooking: unpleasant taste, nothing specificexcept generally offensive egg taste; very dry texture, unusablepreparation.

As can be seen from the table, lowering the pH yielded a better physicaland organoleptic result. The two best samples, HK7927D and HK7927E, werefurther evaluated as described below.

EXAMPLE 4

This example illustrates the effects of combining the egg-yolkpreparations of example 3 with a fruit or vegetable puree in the absenceor presence of added acid.

Sample HK7927E from Example 3 was mixed with 65 g of applesauce to testan acidified food approach and sample HK7927D was mixed with 67 g ofsweet potato puree to test a “low acid” food approach.

The HK7927E sample mixed with applesauce was a much smoother productwith less egg taste. The mixture of HK7927D with sweet potato puree didnot taste as appealing. These results suggest that adding acid in theform of a fruit puree yields a smoother and better tasting composition.

EXAMPLE 5

This example illustrates the effects of adding varying quantities ofvinegar to egg-yolk preparations on pH and physical and organolepticqualities of the composition.

Twenty grams of dried egg yolk were dispersed in 80 g of watercontaining 0 to 12.2 grams of white vinegar standardized to 5% acidity.The dispersions were then placed in sealed glass jars in aboiling/simmering water bath for 20 minutes. After cooling, the taste,tartness, texture and mouthfeel were evaluated. The preparations werethen filtered through filter paper to get a clearer fluid for pHmeasurement. The pH was measured with a portable pH meter. The pH valuesin this example only were corrected for measurement bias using readingsobtained from pH 7.01 and pH 4.01 standards so that reported valuesshould be considered indicative rather than precisely accurate. The pHand sensory observations are shown in Table 3.

TABLE 3 Sample Vinegar (g) pH Observations HK7928A 0.0 6.26 Loosescrambled eggs; lots of clear filtrate; little mealy, dry, gritty; noacidity. HK7928B 3.4 4.85 Creamier than 7928A; slight mealy mouthfeel;no acidity; mildest taste. HK7928C 6.7 4.40 Very creamy; smooth; slightvinegary but good taste. HK7928D 9.1 4.30 Not as creamy, strong vinegartaste, too much. HK7928E 12.2  4.17 Too strong a vinegar taste, verythin, creamy.

It was concluded that HK7928C was the best of the compositions in thisexample because it had a smooth, creamy mouthfeel, an acceptable tasteand a pH less than 4.6. These results suggested that the optimal acidcontent when using acetic acid at 5% acidity was 6.7 g per 20 g of driedegg yolk. This calculates to be 1.675 grams of 100% acetic acid per 100g dried egg yolk, or 28 mEq. This same amount of acid calculated in mEqfor citric acid monohydrate, would be about 2 grams citric acidmonohydrate per 100 g dried egg yolk.

EXAMPLE 6

This example illustrates the use of fruit puree to increase the amountof egg yolk that can be incorporated into the food composition and todecrease the amount of added water.

In order to obtain a composition with a higher percentage of egg yolk,398.2 g of dried egg yolk, 129.5 g of vinegar and 601.1 g of applesaucewere combined (dried egg yolk=35.3% of the mixture). The resultantmixture was, however, too thick to get any dispersion of the dried eggyolk into the fluid ingredients. Water was, therefore, added in gradedportions until about 550 g were added (dried egg yolk=23.7% of themixture). The ingredients could then be blended into a homogeneousmixture. When this was cooked at 175° F. to 180° F. for about 20minutes, the mixture became very thick.

Samples of this mixture were transferred to glass jars and cooked in aboiling/simmering water bath for 30 minutes. The resulting food, codedHK7001A, was very thick and dry; it was not a puree; and it was judgedto be less desirable than formulations in examples 3-5 using lesseramounts of egg-yolk solids.

A 500 g portion of the mixture was combined with an additional 100 g ofapplesauce (dried egg yolk=19.8% of the mixture), blended forhomogeneity and samples placed in glass jars and cooked in aboiling/simmering water bath for 30 minutes. The resulting food, codedHK7001B, was still thick and pasty, but was showing a more appealingflavor and texture. Thus, in order to use the addition of fruit toachieve a more appealing flavor, it is preferable to keep the egg-yolksolids at 20% or less.

Examples 3-6 show that an acceptable approach for preparing acomposition containing egg yolk requires having enough water and acid inthe initial mixture to disperse the dried egg yolks upon blending;blending the mixture to get a smooth dispersion with no lumps;coagulating the egg yolk by cooking the acidified egg-yolk dispersion ata temperature greater than 170° F. (perhaps greater than 175° F.); andblending the heated dispersion containing the coagulated egg yolk tomake a smooth dispersion prior to the final sterilization. Optionally,fruit can be added to improve the flavor.

EXAMPLE 7

This example illustrates a two-phase process for preparing a compositioncontaining 13% dried egg yolks (equivalent to 27% whole egg yolks) andfruit.

Using egg yolks containing 12 mg DHA per gram egg-yolk solids, ababy-food preparation containing about 13% dried egg yolk in a 113-gram(4-ounce) jar of a baby-food preparation will provide 150 mg of DHA in100 grams of baby food. The following process was, therefore, designedto prepare a baby-food composition containing 13% dried egg yolk.

This process involved mixing about 35% dried egg yolks with citric acidmonohydrate and then heating the mixture to greater than 175° F. (80°C.) to denature, i.e. coagulate, the egg-yolk protein (Phase I). Thisphase I composition was then mixed with various fruit purees and theresulting organoleptic characteristics assessed.

For the first phase, a master batch of the Phase I Egg-Yolk Preparationwas prepared with 400 g of dried egg yolks, 8 g of citric acid and 730 gof water. The water was added to a large stainless steel bowl. Thecitric acid was dissolved in the water and then the dried egg yolks wereadded. The larger lumps of egg were broken up with a spoon and then themixture was made into a smooth homogeneous dispersion with a BRAUNMULTIMIXER blender. The dried egg-yolk level was 35.15% of the Phase IEgg-Yolk Preparation.

The bowl was then placed atop a pot with boiling water as a doubleboiler. The temperature of the egg-yolk dispersion was brought to 175°F. to 185° F. The dispersion became thick with this heating, so it wasblended several times to disperse the coagulated egg. The egg in contactwith the hot surface of the bowl was more prone to coagulate due to thehigher local temperature.

The dispersion lost about 58 g of water due to evaporation, which wasreplaced after the dispersion was removed from the heat and then blendedinto the dispersion. Afterwards, one sample was placed in a glass jar,sealed and cooked in a boiling water bath for 30 minutes. The remainingPhase I dispersion was refrigerated and held for blending in Phase II.

For phase II, BEECH-NUT baby fruit puree heated to 150° F., 315 g, wasblended with 185 g of the Phase I Egg-Yolk Preparation, to yield 13.0%dried egg yolk in the mixtures. Samples were placed in glass jars,sealed and heated in a boiling/simmering bath for 30 to 35 minutes. Thethree samples produced were as follows:

TABLE 4 BEECH-NUT Sample PH Fruit Puree Source Product Code HK7005A 4.19BEECH-NUT Stage 3 Pears 6806C1103 HK7005B 4.15 BEECH-NUT Stage 2 Peaches& 7611C1102 Bananas UK7005C 4.02 BEECH-NUT Stage 2 Pears & 7616E1522/24Raspberries

Three jars of each sample were submitted for taste testing. As shown inTable 5, the preparations were reported to taste sour and to be not verypalatable.

TABLE 5 Sample Flavor Evaluation HK7005A 3 - not good 1 - okay 1 -“funny taste” HK7005B 4 - okay 1 - not good HK7005C 4 - not good 1 -okay

EXAMPLE 7

This example illustrates the preparation of a low-acid egg-yolkcomposition using sweet potato puree.

The composition in this example (HK7026) was prepared using thefollowing components in the percentages given as volume percent: sweetpotato puree, 55% (BEECH-NUT Stage 3 Sweet Potatoes, 7313B0755); driedegg yolks, 15%; heavy cream, 5% (40% fat; ingredients milk and cream);ground cinnamon, 0.1%; and water, 24.9% (warm, about 120 degrees). Thewater, heavy cream, warmed sweet potato puree, and cinnamon werecombined in a blender bowl and the dried egg yolk was added. The mixturewas blended and the egg yolk was easily dispersed in one minute.

The mixture was then transferred to a double boiler and heated to 180°F. with stirring. The coagulated material was then blended to produce afine dispersion which was readily achieved. The puree was transferred tosmall Mason jars and retorted for 60 minutes at 15 psig using a homepressure cooker.

The resultant puree had a dried-out, curdled appearance suggesting thatit may have lost some liquid in the pressure cooking process. It ispossible that a lower level of heavy cream such as 2.5% could diminishthe apparent drying out of the puree. The combination of heating in thehome pressure cooker and air entrapment in the purees resulted intextures that were undesirable in appearance. The pH after processingwas 5.41.

The process was replicated in a pilot plant, however, again the productappeared curdled and undesirable in appearance in the jar. Because inprevious work, adding zinc salt reduced the sulfurous odor and taste ofcooked egg yolk, zinc chloride was added to the composition prepared inthe pilot plant. As a result the pilot plant preparation had no egg-liketaste or smell.

EXAMPLE 8

This example illustrates the effects of adding the acidulant, phosphoricacid, on organoleptic properties of the composition.

Four test kitchen samples were prepared containing 15% dried egg yolks,6% medium grain rice flour and 0.011% zinc chloride and the effect ofstep-wise addition of phosphoric acid acidulant on product appearanceand taste was assessed. The ingredients were combined with water andblended to a smooth consistency, the pH was adjusted with phosphoricacid to the appropriate pH between 6.15 and 4.15 and the mixture heatedto 190° F. to coagulate the egg protein. The mixture was then blendedagain to a smooth consistency and retorted for 50 min at 250° F. forpreparations having a pH greater than 4.6 and at 212° F. forpreparations having a pH less than 4.6. The samples were tested fortitratable acidity (post processing), pH (before and after processing)and for color using a Hunterlab colorimeter. The Hunterlab colorimeterquantitated reflectance on an L, a, and b coordinate system. The Lcoordinate axis measured lightedness on a scale increasing fromdarkness-to-lightness; the a axis measured increasing values on acontinuum from green to red; and the b axis measured increasing valueson a continuum from blue to yellow. The results are shown in Table 6.

TABLE 6 TK141A TK141B TK141C TK141D Dried Egg 15.00 15.00 15.00 15.00Yolk, % Rice Flour, % 6.00 6.00 6.00 6.00 Acid added none phosphoricphosphoric phosphoric Acid added % 0.00 0.12 0.19 0.38 Titratable 0.0820.250 0.329 0.534 acidity, % Unprocessed pH 6.15 5.10 4.70 4.15Processed pH 5.93 5.13 4.75 4.25 Retort tempera- 250 250 250 212 ture, °F. Hunterlab “L” 63.79 66.78 68.82 78.71 Hunterlab “a” 3.79 5.06 4.590.28 Hunterlab “b” 23.10 24.76 24.39 23.35

Sample TK141D had the lightest color (highest Hunterlab L value),probably because of the lower retorting temperature of 212° F.

Samples TK141B, TK141C and TK141D were found to have a smoother texturethan sample TK 141A. The samples were then tested for organolepticacceptability. The observations are summarized below.

Sensory Evaluation

TK141A

Appearance in the jar (unopened): heavily curdled, water separation,starch separated, hard plug, dark, and starch gel surrounds plug

Appearance on opening: slimy look on top, plug shrunken away from glass

Odor/smell upon opening: slight cooked egg odor

Appearance on mixing: looks terrible, starch glistening, darkish

Mouthfeel: slightly gritty (better than it looked but well-stirred)

Taste: bland, slight cooked egg taste

TK141B

Appearance in the jar (unopened): finer curd, softer plug, sloppy starchglop at bottom, slightly lighter

Appearance on opening: curdled top, grainy surface

Odor/smell upon opening: cooked egg odor

Appearance on mixing: very curdled and grainy, not attractive, lightercolor than A.

Mouthfeel: grainy, particles softer then A

Taste: bland, cooked egg taste

TK141C

Appearance in the jar (unopened): much finer curd, yellow, less dark,and some starch separation, water separation, soft plug

Appearance on opening: nice yellow color, egg salad textural appearance,flows like baby food, soft plug

Odor/smell upon opening: slight cooked egg odor

Appearance on mixing: grainy, starch gel pieces

Mouthfeel: soft, smooth despite visual appearance of lumps

Taste: slightly tart, not bad

TK141D

Appearance in the jar (unopened): light yellow (great color), looks likesome air bubbles with no obvious curd, no water or starch separation

Appearance on opening: skin on top, creamy color (more white/lessyellow)

Odor/smell upon opening: very slight cooked egg odor

Appearance on mixing: viscous, very thick, grainy, not bad

Mouthfeel: very smooth

Taste: moderately tart, not bad

It was concluded from this experiment that acidification improvesmouthfeel and appearance, in particular, the color of the composition.Reducing the pH to less than pH 4.6 permitted retorting at 212° F. inthe sterilization process and this is apparently why the color of TK141Dwas much lighter than the other preparations as indicated by the higherHunterlab L value.

EXAMPLE 9

The following example illustrates the comparison of three food acidacidulants, phosphoric acid, citric acid and vinegar, which aregenerally recognized as safe for use in baby-food preparations by theU.S. Food and Drug Administration.

Except for the acidulant, compositions were prepared according to theformulations in Example 8 to contain 15% dried egg yolks, 6% mediumgrain rice flour and 0.011% zinc chloride. The acidulants used were 85%phosphoric acid, citric acid monohydrate or vinegar standardized to 5%acidity. The pH of the compositions was adjusted to approximately pH4.15. The ingredients were combined with water and blended to a smoothconsistency, the pH was adjusted to pH 4.15 to 4.20 with the appropriateacid and the mixture was heated to 180° F. for 5 minutes to coagulatethe egg protein. The mixtures were then blended again to a smoothconsistency and retorted at 212° F. for 50 minutes.

Experimental samples were evaluated for flavor and mouthfeel/texture ona standard nine-point hedonic scale. The scale is as follows:

Score/rating Std. Hedonic Scale 9 I like extremely 8 I like very much 7I like moderately 6 I like slightly 5 I neither like nor dislike 4 Idislike slightly 3 I dislike moderately 2 I dislike very much 1 Idislike extremely

The results are shown in Table 7.

TABLE 7 TK141D TK159A TK159B TK159C Dried Egg Yolk, % 15.00 15.00 15.0015.00 Rice Flour, % 6.00 6.00 6.00 6.00 Acid added phosphoric phosphoriccitric vinegar Acid added, % 0.38 0.37 0.39 10.64 Unprocessed pH 4.154.16 4.15 4.17 Processed pH 4.25 4.28 4.25 4.27 Retort temperature, 212212 212 212 ° F. Hunterlab “L” 78.71 74.75 74.06 76.55 Hunterlab “a”0.28 1.08 1.10 0.81 Hunterlab “b” 23.35 23.87 25.16 23.47 Flavor(nine-point 2.05 2.89 2.44 1.22 scale) Mouthfeel/Texture 3.84 5.66 6.676.33 (nine-point scale)

As shown in the table, TK159C, made with white vinegar, had the worsttaste. Phosphoric acid and citric acid were roughly similar on taste andcitric acid may be slightly better for mouthfeel. Samples made with allthree acids, which were retorted at 212° F., had good light yellowcolors.

Although sample TK159A containing phosphoric acid was most acceptable ontaste, citric acid is preferred for use as the acidulant rather thanphosphoric acid. TK141D contained 0.38% phosphoric acid and TK159Acontained 0.37% phosphoric acid. Since 85% phosphoric acid containsabout 26% phosphorus, these two samples would contain about 112milligrams of added phosphorus in a four-ounce jar (0.38%=380 mg %; 380mg/100 g×113 g×0.26% P=112 mg P/jar). Egg yolks already contain about100 milligrams of phosphorus per medium egg yolk, which weighs 17g. A15% dried egg-yolk composition contains the equivalent of 30% liquid eggyolk, or 33.9 g (two egg yolks) per four-ounce (113 gram) jar, whichsupply 200 mg of phosphorus just from the two egg yolks. The recommendeddaily intake (RDI) for phosphorus for the infant is 500 mg, so a foodacidified with phosphoric acid would provide 60% of the recommendeddaily intake (“RDI”) of phosphorus. Food acidified with any other acidwould still provide 40% of the phosphorus RDI, derived from the egg yolkalone.

EXAMPLE 10

This example illustrates the effect of retort temperature and sugarcontent on the organoleptic properties of compositions.

Except for the acidulant used, compositions were prepared according tothe formulations in Example 8 to contain 15% dried egg yolks, 6% mediumgrain rice flour and 0.011% zinc chloride. Where required, citric acidwas used to adjust to pH and table sugar was added at 9%. Theingredients were combined with water and blended to a smoothconsistency, the pH was adjusted with citric acid monohydrate to pH 4.15to 4.20 as appropriate and the mixture was heated to 180° F. for 5minutes to coagulate the egg protein, blended again to a smoothconsistency and retorted for 50 minutes at either 250° F. or 212° F. Inorder to assess the effect of temperature on the compositions, TK162Band TK159B, which were otherwise equivalent preparations, were retortedat 250° F. and 212° F., respectively. Because the pH of the compositiondetermines the required retort temperature, i.e., compositions having apH greater 4.6 need to be retorted at 250° F. and compositions having apH of 4.6 or less need only to be retorted at 212° F., referencecomposition TK141A having pH of about 6 was compared to compositionTK162B in order to compare the effect of added acid and retorttemperature on organoleptic characteristics of the composition. Finally,composition TK162C was prepared in the same manner as TK159B except that9% sugar was added to test the effect on organoleptic characteristics ofthe composition. The results are shown in Table 8.

TABLE 8 TK141D TK162B TK159B TK162C Dried Egg Yolk, % 15.00 15.00 15.0015.00 Rice Flour, % 6.00 6.00 6.00 6.00 Sugar, % none none none 9.00Acid added, % none citric citric citric (0.38) (0.39) (0.38) UnprocessedpH 6.15 4.15 4.15 4.15 Processed pH 5.93 4.25 4.25 4.25 Retorttemperature, 250 250 212 212 ° F. Hunterlab “L” 63.79 68.65 74.06 73.11Hunterlab “a” 3.79 4.87 1.10 1.71 Hunterlab “b” 23.10 24.80 25.16 25.32Flavor (nine-point scale) 3.84 1.95 2.44 4.86 Mouthfeel/Texture 4.534.00 6.67 6.64 (nine-point scale)

The results from these compositions show that acidifying the compositiondetracts from flavor by introducing a strong tartness but enhances colorretention, even when the acidified sample is retorted at 250 F.Retorting at a lower temperature is most favorable for maintaining alight color, i.e., higher Hunterlab “L” values. Processing at a lowertemperature also favors a better mouthfeel and texture. The experimentabove further showed that flavor can be improved by adding sugar tobalance the added acid. The 9% sugar level in this model system yieldeda relatively neutral flavor score of 4.86.

EXAMPLE 11

This example illustrates baby-food compositions containing 15% dried eggyolk, citric acid monohydrate as acidulant, zinc chloride and variousfruit purees or juices as sugar sources.

The compositions in this example were prepared essentially as describedabove in examples 3-10 which was, briefly, as follows. All ingredientsexcept the citric acid were combined and blended together. The pH wasthen determined and adjusted to pH 4.25 or less with citric acid. Themixture was then transferred to a double boiler and heated to 170° F. to180° F. to coagulate the egg protein. The hot mixture was then blendedagain until smooth and then filled at 150° F. into glass jars which werecapped and processed for 50 to 55 minutes at the indicated temperature.The compositions were as shown in Table 9.

TABLE 9 TK152 TK153A TK153B TK153C K154B K154C K155 Dried Egg Yolk, %15.0 15.0 15.0 15.0 15.0 15.0 15.0 Apple Puree 55.0 58.0 55.0 25.0 Pearpuree 57.0 59.0 Sweet Potato puree 25.0 Yogurt 25.0 15.0 Grape jc. Conc.10.0 5.0 3.0 Apple jc. Conc. 7.0 7.0 7.0 10.0 Rice flour, med. 3.0 3.03.0 3.0 3.0 3.0 grain Cinnamon 0.045 Zinc chloride 0.011 0.011 0.0110.011 0.011 0.011 0.011 Citric acid to: pH pH pH pH pH pH pH 4.23 4.234.26 4.26 4.24 4.23 4.25 Water q.s. q.s. q.s. q.s. q.s. q.s. q.s. 100100 100 100 100 100 100 Retort temp, 250° F. 212° F. 212° F. 212° F.212° F. 212° F. 212° F. ° F. Titratable acid,% 0.414 0.437 0.560 0.5150.469 0.810 Total sugars, % 7.7 8.9 7.3 5.9 4.8 7.7

Composition TK 153C was judged the best on flavor, which is probably dueto the additional cinnamon flavor notes which effectively neutralizedthe cooked egg-yolk flavors.

EXAMPLE 12

This example illustrates further testing of composition, TK153C fororganoleptic acceptability.

TK153C was prepared as described in Example 11 and coded as TK163 fororganoleptic analysis by a trained panel of 22 panelists using anine-point hedonic scale as described in Example 9. TK163 was evaluatedfor appearance/color, flavor and mouthfeel/texture on a nine-point scalehedonic scale. The results are shown in Table 9 below.

TABLE 10 Attribute Mean Value Appearance/Color 5.95 Flavor 5.95Mouthfeel/Texture 6.23

Since the average hedonic score was above neutral for each of the threetested organoleptic characteristics, sample TK163 was deemed to be anorganoleptically acceptable baby-food preparation containing 15% driedegg yolk.

EXAMPLE 13

This example illustrates a testing procedure that could be used todetermine the organoleptic acceptability of baby-food composition toinfants.

Informed consent would be obtained from the parents of the infantsinvolved in the study. Testing would be in a double-blind, randomizedcontrolled study. Approximately 10 full-term infants of ages from about4 months to about 12 months would be fed a series of baby-foodcomposition including a composition containing egg yolk and a controlstandard baby food composition known to be accepted by infants. Thiscontrol composition will serve as a reference for organolepticacceptability. The baby-food compositions can be prepared, for example,by the methods identified in Examples 3-12 above.

General data on the infants would be obtained and recorded such as ageand weight. In addition, background information would be obtained fromthe parent which would generally identify food preferences or aversionsas well as eating habits of the family of the test infant. Subjectswould be randomly assigned to one of the two feeding groups. The testwould involve feeding of the infant by the adult parent. The parentwould record the acceptability and tolerance of the infant toward thebaby food including amount offered, amount consumed and amount refusedby the babies. All digestive problems, such as vomiting, spitting up,and diarrhea would be noted. Acceptability would be scored by themothers in a questionnaire which uses a nine-point hedonic scale asillustrated in Example 9 above (see also Stone and Sidel, SensoryEvaluation Practices, Academic Press, Inc., Orlando, 1985, pp. 58-86which is incorporated by reference). The mothers would indicateacceptance or aversion based on the responses of the infants to thefood. The results would then be analyzed and egg-yolk compositionsshowing acceptance comparable to or greater than that of standard babyfood would be considered suitable for use as an infant food.

EXAMPLE 14

This example illustrates an egg yolk containing composition of peaches,oatmeal and cinnamon in which the acidulant is comprised of an acidicfruit component of peach puree and white grape juice along with ascorbicacid.

This study, identified as PP6300, was a pilot plant scale up of anearlier Test Kitchen sample, TK341C. TK341C was evaluated by a panel offive (5) tasters and found to have an acceptable taste.

Single-strength peach puree, 82.5 lb., was added to a kettle equippedwith a swept-surface heating capability. The puree was heated to atemperature of 160° F. to 170° F. using the hot water jacket. Fifty-five(55) pounds of this hot peach puree were weighed and transferred to asecond kettle.

Ferrous sulfate heptahydrate, 0.03 lb. (13.62 g), and citric acid, 0.02lb. (9.08 grams), were dissolved in a portion of the batch water to forma complex of ferrous iron and citric acid. Seven pounds of white grapejuice concentrate, 6.67 lb. of dried egg-yolk powder, 2.0 lb. of oatflakes, 0.04 lb. of ascorbic acid, 0.45 lb. of ground cinnamon, 0.02 lb.(9.08 g) of vitamin premix and 0.011 lb. (5.0 g) of zinc sulfate wereadded to 18.07 lb. of batch water in the second kettle containing 55pounds of peach puree and made into a slurry with the hot peach puree.The ferrous sulfate-citric acid solution was added and mixing wascontinued.

The slurry was passed through a Stephan Microcutter, Model No. MC-12,equipped with a blank ring and transferred to a Koven kettle. Afteradditional mixing, the pH was measured and found to be pH 4.04. Thepeach puree and white grape juice concentrate contributed sufficientacidity so that addition of a specific acidulant was unnecessary. Theslurry was heated to a temperature of 180° F. to 190° F. by steaminjection, adding about 10 lb. of water to the batch via condensation.The slurry was passed twice through a Stephan Microcutter, Model No.MC-12, equipped with a 0.05-0.10 mm ring and strained through a 0.033″screen.

The product was filled into 113-gram glass jars at a temperature of 150°F. The jars were then capped and thermally processed in a retort at 212°F. for 30 minutes to achieve pasteurization in accordance with 21 C.F.R.§114 et seq. “Acidified Foods.” The pH of PP6300 on the day afterprocessing was 4.34.

EXAMPLE 15

This example illustrates pilot plant production of an egg yolkcontaining chicken lasagna composition (PP6627) in which the acidulantis comprised of tomato puree.

Water was heated in an open kettle to 200° F. and 11.25 lb. of mafaldapasta was blanched therein for 10 minutes to achieve hydration. Theblanched pasta was then drained and rinsed with cold water. The weightof the blanched pasta was 26.65 lb.

Forty and one-quarter lb. of frozen carrot pieces were placed in aFitzpatrick Comminutor, Model No. D, at medium speed and an exittemperature of 180° F. to 200° F. (190° F. target). Approximately 6 lb.of water were added through steam injection, resulting in a total pureeweight of 47 lb. The spinning knives in the Comminutor and the injectedsteam comminuted the carrots into a puree that passes through a{fraction (3/16)}″ or ¼″ screens.

Thirty-five pounds of tomato paste, 26.65 lb. of blanched mafalda pasta,20.12 lb. of carrot puree, 17.88 lb. of finely ground chicken, 16.68 lb.of dried egg-yolk powder, and 12.5 lb. of grated Romano cheese wereadded to 91.17 lb. of batch water in a kettle and mixed into a slurry.

The slurry was passed through a Stephan Microcutter, Model No. MC-12,equipped with a blank ring and transferred to a Koven kettle. Afteradditional mixing, the pH was measured and found to be pH 5.0 due to theacidity contributed by the tomato paste. The slurry was heated to atemperature of 180° F. to 190° F. by steam injection, adding about 30lb. of water to the batch via condensation. The slurry was passed twicethrough a Stephan Microcutter, Model No. MC-12 equipped with a 0.05-0.10mm ring and strained through a 0.033″ screen.

The product was filled into 113-gram glass jars at a temperature of 170°F. The jars were then capped and thermally processed in a retort at 250°F. for 45 minutes as required by 21 C.F.R. §113 et seq. “ThermallyProcessed Low-Acid Foods Packaged in Hermetically Sealed Containers.”The pH of PP6627 on the day after processing was 4.96.

PP6627 was evaluated by a trained individual for flavor on a nine-pointscale. A score of “5” means “I neither like nor dislike” and a score of“6” means “I like slightly.” PP6627 was given a score of “6” on thisflavor scale.

EXAMPLE 16

This example illustrates pilot plant production of an egg yolkcontaining pear berry medley composition (PP6331) in which the acidulantis comprised of pear puree, white grape juice, red raspberry puree,elderberry juice concentrate and ascorbic acid.

This study was a pilot plant scale up of an earlier Test Kitchen sample,TK337C. TK337C was evaluated by a panel of five (5) tasters and found tohave a highly acceptable taste by all five tasters.

Single-strength pear puree, 125 lb., was added to a kettle equipped witha swept-surface heating capability. The puree was heated to atemperature of 160° F. to 170° F. using the hot water jacket. Onehundred and eleven pounds of this hot pear puree were weighed andtransferred to a second kettle.

Twenty-five pounds of white grape juice concentrate, 16.68 lb. of driedegg-yolk powder, 20.0 lb. of red raspberry puree, 14.0 lb. of heavycream, 12.5 lb. of full-fat yogurt, 8.75 lb. of medium grain rice flour,7.5 lb. of fresh whole milk, 3.75 lb. of elderberry juice concentrate,0.1 lb. of ascorbic acid, 0.0275 lb. of zinc sulfate were added to thepear puree and 13.2 lb. of batch water in the second kettle and mixedinto a slurry.

The slurry was passed through a Stephan Microcutter, Model No. MC-12,equipped with a blank ring and transferred to a Koven kettle. Afteradditional mixing, the pH was measured and found to be pH 4.14. Theacidic nature of the peach puree and white grape juice concentratecreated sufficient acidity so that addition of a specific acidulant wasunnecessary. The slurry was heated to a temperature of 180° F. to 190°F. by steam injection, adding about 17.5 lb. of water to the batch viacondensation. The slurry was passed twice through a Stephan Microcutter,Model No. MC-12, equipped with a 0.05-0.10 mm ring and strained througha 0.033″ screen.

The product was filled into 113-gram glass jars at a temperature of 150°F. The jars were then capped and thermally processed in a retort at 212°F. for 30 minutes to achieve pasteurization in accordance with 21 C.F.R.§114 et seq. “Acidified Foods.” The pH of PP6331 on the day afterprocessing was 4.08.

All references cited in this specification are hereby incorporated byreference. The discussion of the references herein is intended merely tosummarize the assertions made by their authors and no admission is madethat any reference constitutes prior art. Applicants reserve the rightto challenge the accuracy and pertinency of the cited references.

In view of the above, it will be seen that the several advantages of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above methods and compositionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description shall be interpreted asillustrative and not in a limiting sense.

What is claimed is:
 1. A baby-food composition comprising from about 5%to about 25% coagulated egg-yolk solids (grams/100 grams) and anacidulant in an acceptable, shelf-stable baby-food preparation for whichAppearance/Color, Flavor, and Mouthfeel/Texture scores on a nine-pointhedonic scale are each greater than five, wherein the acidulantcomprises an acid, a cultured food substance containing lactic acid, ora fruit of vegetable component which contributes acidity to thecomposition.
 2. The baby-food composition according to claim 1 whereinthe fruit or vegetable component comprises a puree or juice of apples,pears, pineapples, strawberries, raspberries, elderberries, blueberries,cherries, grapes, peaches, plums, apricots, lemons, clementines,grapefruits, oranges, tomatoes, rhubarbs, sorrels, cress or acombination thereof.
 3. The baby-food composition according to claim 1wherein the acid comprises citric acid, ascorbic acid, phosphoric acid,vinegar or a combination thereof.
 4. The baby-food composition accordingto claim 1 wherein the cultured food substance containing lactic acid isselected from the group consisting of yogurt, sour cream, cottagecheese, sauerkraut and a combination thereof.
 5. The baby-foodcomposition according to claim 1, which has a pH of about 5.0 or less.6. The baby-food composition according to claim 5, which has a pH ofabout 4.6 or less.
 7. The baby-food composition according to claim 1,which comprises from about 5% to about 10% coagulated egg-yolk solids(grams/100 grams).
 8. The baby-food composition according to claim 7,which comprises about 6.7% coagulated egg-yolk solids (grams/100 grams).9. The baby-food composition according to claim 8 further comprising azinc salt, a spice, a filler substance or a combination thereof.
 10. Thebaby-food composition according to claim 9 comprising about 6.7%coagulated egg-yolk solids (grams/100 grams), about 55% peach puree(grams/100 grams), about 7% white grape juice (grams/100 grams), about2% oat flakes (grams/100 grams), about 0.04% ascorbic acid (grams/100grams), about 0.45% cinnamon (grams/100 grams) and about 0.011% zincsulfate (grams/100 grams).
 11. The baby-food composition according toclaim 9 comprising about 6.7% coagulated egg-yolk solids (grams/100grams), about 14% tomato paste (grams/100 grams), about 11% blanchedpasta (grams/100 grams), about 8% carrot puree (grams/100 grams), about7% ground chicken (grams/100 grams), and about 5% grated cheese(grams/100 grams).
 12. The baby-food composition according to claim 9comprising about 6.7% coagulated egg-yolk solids (grams/100 grams),about 44% pear puree (grams/100 grams), about 10% white grape juice(grams/100 grams), about 8% raspberry puree (grams/100 grams), about5.6% cream (grams/100 grams), about 5% yogurt (grams/100 grams), about3.5% rice flour (grams/100 grams), about 3% milk (grams/100 grams),about 1.5% elderberry juice concentrate (grams/100 grams), about 0.04%ascorbic acid (grams/100 grams), about 0.011% zinc sulfate (grams/100grams).
 13. A method for preparing a baby-food composition containingegg yolk, the method comprising combining about 5% to about 25%coagulated egg-yolk solids (grams/100 grams), an aqueous liquid, and anacidulant in an acceptable, shelf-stable baby-food preparation for whichAppearance/Color, Flavor, and Mouthfeel/Texture scores on a nine-pointhedonic scale are each greater than five, wherein the acidulantcomprises an acid, a cultured food substance containing lactic acid, ora fruit of vegetable component which contributes acidity to thecomposition.
 14. The method according to claim 13 wherein the fruit orvegetable component comprises a puree or juice of apples, pears,pineapples, strawberries, raspberries, elderberries, blueberries,cherries, grapes, peaches, plums, apricots, lemons, clementines,grapefruits, oranges, tomatoes, rhubarbs, sorrels, cress or acombination thereof.
 15. The method according to claim 13 wherein theacid comprises citric acid, ascorbic acid, phosphoric acid, vinegar or acombination thereof.
 16. The method according to claim 13 wherein thecultured food substance containing lactic acid is selected from thegroup consisting of yogurt, sour cream, cottage cheese, sauerkraut and acombination thereof.
 17. The method according to claim 13, wherein thecomposition has a pH of about 5.0 or less.
 18. The method according toclaim 17, wherein the composition has a pH of about 4.6 or less.
 19. Themethod according to claim 13, wherein the composition comprises fromabout 5% to about 10% coagulated egg-yolk solids (grams/100 grams). 20.The method according to claim 19, wherein the composition whichcomprises about 6.7% coagulated egg-yolk solids (grams/100 grams). 21.The method according to claim 13 wherein combining about 5% to about 25%egg-yolk solids (grams/100 grams), an aqueous liquid, and an acidulantcomprises combining about 5% to about 25% egg-yolk solids (grams/100grams) and a fruit juice which contributes water and acidity to thecomposition.
 22. The method according to claim 20 further comprisingadding a zinc salt, a spice, a filler substance or a combinationthereof.
 23. The method according to claim 22 comprising combining about6.7% coagulated egg-yolk solids (grams/100 grams), about 55% peach puree(grams/100 grams), about 7% white grape juice (grams/100 grams), about2% oat flakes (grams/100 grams), about 0.04% ascorbic acid (grams/100grams), about 0.45% cinnamon (grams/100 grams) and about 0.011% zincsulfate (grams/100 grams).
 24. The method according to claim 22comprising combining about 6.7% coagulated egg-yolk solids (grams/100grams), about 14% tomato paste (grams/100 grams), about 11% blanchedpasta (grams/100 grams), about 8% carrot puree (grams/100 grams), about7% ground chicken (grams/100 grams), and about 5% grated cheese(grams/100 grams).
 25. The method according to claim 22 comprisingcombining about 6.7% coagulated egg-yolk solids (grams/100 grams), about44% pear puree (grams/100 grams), about 10% white grape juice (grams/100grams), about 8% raspberry puree (grams/100 grams), about 5.6% cream(grams/100 grams), about 5% yogurt (grams/100 grams), about 3.5% riceflour (grams/100 grams), about 3% milk (grams/100 grams), about 1.5%elderberry juice concentrate (grams/100 grams), about 0.04% ascorbicacid (grams/100 grams), about 0.011% zinc sulfate (grams/100 grams).